Author(s)

J.L. de Mol van Otterloo & J.Th.M. De Hosson

Abstract

Microscopic clarifications for the increased hardness of laser melted Al-Cu alloys J.L. de Mol van Otterloo, J.Th.M. De Hosson Department of Applied Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands Abstract Both mechanical and electron microscopic studies have been carried out on la- ser treated aluminium copper alloys with copper concentrations in the range 0-40 wt.%. It is found that a Vickers hardness of 470 kgf/mnf can be attained, which is high compared to a value of 120 kgf/mnf for conventionally heat treated Dural. The microstructure, which causes this difference in hardness, is analysed by transmission electron microscopy. The findings are: Al^Cu strong localized obstacles, Al-A^Cu interfacial energy, cellular to lamellar transition, orientation relationships and misfit dislocations. All these features effect hard- ness in their own way. Based on a composite model of the microstructure the hardness vs laser scan velocity could be predicted in fair

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